As was mentioned earlier....the most common culprit with malfunctioning autos is the magazines. Weak springs, bent feed lips, etc. You mentioned that you were going to try some " round nose bullets" . Some manufactures have loaded some of their rimfires with bullets resembling " truncated cones" . Like Remington' s Viper and Yellow Jacket loads for instance. Sometimes these bullets with a " squarer profile" will catch on the feed ramp....causing problems. If you have been trying a bullet shape of that type..try the round nose configuration. It may solve the problem. (Also, as you aluded to, you can sometimes eliminate feeding problems by simply NOT loading the magazine to its fullest capacity. If by reducing the magazine capacity by one round....that is a simple fix. Try some magazines by other manufacturers and see how they perform!)

Good luck!